What is the "relative IBU strength" of a pellet hop with respect to whole leaf?

[Silver_Is_Money]

It seems that the world of IBU calculators has nearly universally accepted that pellet hops yield on a weight for weight basis 10% more IBU's than do whole leaf or plug hops. But is this true? What did the major players in hop IBU bitterness calculation have to say about pellets?

1) Tinseth never stated, and definitively states that he never once tested a pellet hop. His is quoted only as stating that for pellet hops "all bets are off".

2) Daniels said pellet IBU's are likely between 1 and 1.25 times those of leaf.

3) Garetz said 1.1 times as strong as leaf (or 10%). He is the source of the 10% we accept today as gospel.

4) Mosher said pellets yield 1.33 times more IBU's than leaf.

5) I'm not aware of Rager's opinion here.

6) Noonan scales the IBU's of pellets from 1.0 to 1.5 times the IBU's of leaf based upon remaining boil time.

And all of these men are essentially merely guessing. And their guesses are well dated and hearken back to pellet infancy, when production and storage methods likely yielded pellets with noticeably less "retained over time" IBU strength than the pellets of today. So why do we generally delude ourselves into a firm acceptance of 1.1X or 10%? And then worse yet, impose this factor upon the Tinseth model.

Personally I believe the truth for modern pellets more likely lies somewhere in the range of pellets yielding in the range of 25% more IBU's than leaf. But this is also merely a guess based upon my taste buds.

 

[Silver_Is_Money]

Perhaps Nononan is the most correct here, as he places pellets at 50% more strength than leaf at 15 minutes or less remaining in the boil and on an equivalence basis (or 1:1 unity) with leaf for what I must guess to be 60-90 minutes of boil time. If it takes a leaf hop 60 to 90 minutes of boil time to reach maximum utilization, and pellet hops utilization is effectively far more akin to instantaneous, then for both forms the IBU strength multiplier for the 60-90 minute boil time range would be 1X, simply based upon their weight. And by 15 or less minutes in the boil the pellet is perceived by Noonan to yield 50% more IBU's. Intuitively, this approach seems to make the most sense to me.

 

[TheMadKing]

So that's a really complex question.

What you're really asking is what is the oz for oz difference in hop utilization between pellets and whole cone.

A couple things to consider:

Hope utilization is the percentage of alpha acids that isomerized during the boil.

IBU is the parts per million of isomerized alpha acid in beer. This is a function of the solubility of the alpha acid in your wort (pH), your boil time, your boil temperature (altitude), and your surface area in contact with the hops.

A pound of feathers weighs the same amount as a pound of lead. So since the weight is the same, only the volume has changed.

Pellets simply have more surface area in contact with wort which increases the speed at which alpha acids can dissolve into your wort.

As homebrewers we have the luxury to assume 100% hop utilization meaning that we can ignore boil time and temperature. So the only real difference is the amount of alpha acid that is dissolving into solution.

Now I'm venturing into the guessing phase, that because our volume ratios are so different from a professional brewing system, we will dissolve close to 100% of the alpha acids no matter which hop format we choose.

That means that on the homebrew scale, there's no difference whatsoever between pellets and whole cone.

At the pro scale, they are dealing with hop utilization in the 30% range so it would have a much larger impact.

 

[dmtaylor]

I'm not sure. I accept the approximate 10% notion, but have never officially tested it, as I don't have easy access to a photospectrometer or whatever the hell, and have not yet run side by side experiments to taste two beers with whole vs. pellet. Anyone interested should do one or both.

Personally, I'm not all that interested. I use whole hops from my garden for bittering, and over the years I've learned their approximate bittering capability well enough not to care what the exact numbers are. And on the other hand, I use pellets for everything else, which have become the industry standard and which nearly everyone knows and understands better than anything else. So, I don't really see the need, personally. But I can understand why we should be interested, for purposes of recipe conversions or whatnot. Just saying that I personally probably won't run experiments on this for quite some time if ever.

 

[Silver_Is_Money]

It apparently takes 60-90 minutes to fully rupture and expose the lupulin glands of whole (leaf or plug) hops and release their AA's which make for bitterness IBU's. Pellet hops lupulin glands are totally ground up and about as ruptured as they can be right out of the starting gate. It seems intuitive from this that they would make for leagues more late addition IBU bitterness contribution than would whole hops. Additionally pellets seem more likely to contribute to a distinct off flavor which has been termed "hop bite". Fortunately hop bite ages out and diminishes somewhat over time.

 

[Silver_Is_Money]

The most severe test of this would likely be for a lab to measure the IBU's of a beer hopped solely via 170 degree F. or lower whirlpool, for totally identical beers sans for leaf and pellet hops.

 

[Vale71]

And all of these men are essentially merely guessing.

And there's your answer. All these formulas for predicting IBUs in finished beer are merely guesswork. You can expect deviation of as much as 50% less or 100% more than what they predict in real-life situations. I think estimating the difference between using whole hops or pellets just adds one more level of guesswork and is really as worthwhile as a discussion about the sex organs of angels.

 

[BrewnWKopperKat]

It seems intuitive from this that they would make for leagues more late addition IBU bitterness contribution than would whole hops.

For hop pellets, there's one set of recent data I'm aware of that appears to support your intuition. It's in a presentation associated with Basic Brewing Radios "November 1, 2018 - IBUs vs Wort Gravity and Hop Stand Temps" episode.

For the measurements, there are four sets of samples (see slide 8). Wort was boiled for 120 min. Samples taken at 1 min, 5 min, 10 min, and every 10-15 minutes afterward. Wort boiled, then temperature reduced to 70°C, 80°C, or 90°C. Samples taken at 1 min, 5 min, 10 min, 20 min, 30 min, and 40 min

Summary charts on slides 14 and 19.

 

[Vale71]

As homebrewers we have the luxury to assume 100% hop utilization meaning that we can ignore boil time and temperature. So the only real difference is the amount of alpha acid that is dissolving into solution.

Now I'm venturing into the guessing phase, that because our volume ratios are so different from a professional brewing system, we will dissolve close to 100% of the alpha acids no matter which hop format we choose.

That means that on the homebrew scale, there's no difference whatsoever between pellets and whole cone.

At the pro scale, they are dealing with hop utilization in the 30% range so it would have a much larger impact.

Sorry to engage you personally again, but you're talking nonsense once more. Hop utilization is the percentage of alpha-acids (iso and non-iso) that dissolve into solution. How can you ignore it while expending great effort trying to estimate it? And of course boil-time and temperature do affect utilization in any setting, we are not somehow exempt from the laws of physics and chemistry.

And you are right that differences in volumes and processes at the HB level impact hop utilization, you just went in the wrong direction and kept running until you hit the wall at the end. Hop utilization is lower at the HB level and often doesn't reach 25%. If we did indeed get 100% our beers would be on average four times more bitter than what we'd expect and basically undrinkable. You will only get 100% utlization at any level if you use pre-isomerized downstream products, but that's because as the name implies alpha-acids have already been fully isomerized by means of physical and chemical processes.

 

[Silver_Is_Money]

For hop pellets, there's one set of recent data I'm aware of that appears to support your intuition. It's in a presentation associated with Basic Brewing Radios "November 1, 2018 - IBUs vs Wort Gravity and Hop Stand Temps" episode.

For the measurements, there are four sets of samples (see slide 8). Wort was boiled for 120 min. Samples taken at 1 min, 5 min, 10 min, and every 10-15 minutes afterward. Wort boiled, then temperature reduced to 70°C, 80°C, or 90°C. Samples taken at 1 min, 5 min, 10 min, 20 min, 30 min, and 40 min

Summary charts on slides 14 and 19.

Interesting indeed!!! Would you please provide the web link?

 

[BrewnWKopperKat]

Would you please provide the web link?

Here's the direct link to the PDF:

http://hwcdn.libsyn.com/p/3/a/c/3ac...58187136&hwt=fcb08b1bbf86ecbf7e65b03d555da999

For future readers, if the direct link is broke, check the Nov 1, 2018 show notes for an updated link:
http://www.basicbrewing.com/index.php?page=basic-brewing-radio-2018

 

[dmtaylor]

It apparently takes 60-90 minutes to fully rupture and expose the lupulin glands of whole (leaf or plug) hops and release their AA's which make for bitterness IBU's.

No way in hell.

The more we talk about this, the more I'm inclined to think there's zero difference in utilization between whole vs. pellet.

 

[Silver_Is_Money]

No way in hell.

The more we talk about this, the more I'm inclined to think there's zero difference in utilization between whole vs. pellet.

Even at the low end of remaining boil minutes?

 

[Vale71]

Pellet hops lupulin glands are totally ground up and about as ruptured as they can be right out of the starting gate.

No they're not, and thank heaven for that. If they were then the contents would be exposed to oxygen and quickly turn stale, in reality pellets are even more resistant to oxydation than whole cone hops because there is no air inside the pellet. Lupilin glands are simply somewhat separated from the rest of the vegetable matter and will disperse more quickly and thoroughly in boiling wort, leading to a slightly elevated utilization. By how much is IMHO anybody's guess.

Just to put things into perspective, no respectable commercial brewery would even try to estimate hop utilization using any of the three formulas. They just continuously test wort and beer as part of their quality assurance process and then determine the actual utilization factor and continuously feed it back to production for any necessary adjustment to take place.

 

[Vale71]

Even at the low end of remaining boil minutes?

That's when you would probably get the greatest difference, because as I mentioned in my other post lupulin disperses more quickly when using pellets and this gains in relevance the shorter the boil time is. Over 90 minutes it might make almost no difference, at flame-out the difference might be perceivable.

 

[Silver_Is_Money]

That's when you would probably get the greatest difference, because as I mentioned in my other post lupulin disperses more quickly when using pellets and this gains in relevance the shorter the boil time is. Over 90 minutes it might make almost no difference, at flame-out the difference might be perceivable.

This would agree (qualitatively, though not quantitatively) with Noonan's assessment. He said 1:1 (or no difference) for longer boil times, and 1.5:1 (a noticeable difference) for shorter boil times.

 

[Silver_Is_Money]

Here's the direct link to the PDF:

http://hwcdn.libsyn.com/p/3/a/c/3ac...58187136&hwt=fcb08b1bbf86ecbf7e65b03d555da999

For future readers, if the direct link is broke, check the Nov 1, 2018 show notes for an updated link:
http://www.basicbrewing.com/index.php?page=basic-brewing-radio-2018

It would have been more revealing if they had added leaf hops into the mix.

 

[dmtaylor]

Even at the low end of remaining boil minutes?

Oh, okay, I see your point.

 

[TheMadKing]

Sorry to engage you personally again, but you're talking nonsense once more. Hop utilization is the percentage of alpha-acids (iso and non-iso) that dissolve into solution. How can you ignore it while expending great effort trying to estimate it? And of course boil-time and temperature do affect utilization in any setting, we are not somehow exempt from the laws of physics and chemistry.

And you are right that differences in volumes and processes at the HB level impact hop utilization, you just went in the wrong direction and kept running until you hit the wall at the end. Hop utilization is lower at the HB level and often doesn't reach 25%. If we did indeed get 100% our beers would be on average four times more bitter than what we'd expect and basically undrinkable. You will only get 100% utlization at any level if you use pre-isomerized downstream products, but that's because as the name implies alpha-acids have already been fully isomerized by means of physical and chemical processes.

You're right about the hop utilization not being 100%, I was thinking of Beer Smith which uses 100% as a scaling factor for perceived bitterness. My bad.

The rest of your insulting post is basically not understanding what I said and then arguing with it.